1. Field
This invention relates to multi-purpose vehicles. Specifically, it related to an improved light weight, highly efficient U-shaped multi-purpose service vehicle particularly adapted for airport, digging, and surface transport applications.
2. State of the Art
Numerous multi-purpose vehicles are known. These vehicles typically employ an X-shaped, or box-shaped frame with a conventional cab on the front, and a cabin or bed attached along the length of the frame, such as the amphibious vehicle designed by Fletcher et al., U.S. Pat. No. 2,923,268. Generally, the conventional multi-purpose vehicle has forward steering wheels and rear drive wheels. When pulling heavy objects, a number of conventional vehicles may be harnessed together in series. This requires a long pulling space to accommodate the aligned vehicles connected in series. These harnessed vehicles are also difficult to turn and cause the rear vehicles to run in the tracks left by the forward vehicles; often times resulting in poor traction of the trailing vehicles. The aligned vehicles, when harnessed, generally move in a longitudinal direction. Non-pivoting wheels of conventional vehicles do not allow significant sideward movement, which makes it necessary to uncoupled and recouple the vehicles when it is necessary to move the load laterally.
To shorten the turning radius of conventional vehicles, articulated vehicles, such as those described in Hutt, U.S. Pat. No. 4,249,629, and Domenighetti, U.S. Pat. No. 2,914,065 have been utilized. In other applications, a series of carts pulled by a main drive vehicle may be employed, such as the Fire Fighting and Rescue Apparatus described by P. F. Cummins, U.S. Pat. No. 2,169,581. Although these articulated vehicles enable a series of harnessed vehicles to turn in a shorter radius, they do not solve the problem of the rear aligned vehicle's poorer traction as it travels in the same tracks left by the forward vehicles.
The confined working space in underground mines also requires compactness in self loading hauler (SLH) vehicle designs. As a result, SLH vehicles tend to have a length slightly greater than a light hauling vehicle. The excessive length is tolerable in a majority of underground operations since the drifts (tunnels) are long in comparison and have a narrow width and low height. The excessive length of the SLH contributed to counter-balancing the oversized payloads. However, the narrow width complicates turning and side slope stability. This requires judicious design of the basic frame structure and the location of the components within it. Low height is not only desirable from an operating stand-point, but is also necessary in order to improve the stability of the SLH.
British Patent 1,203,338 incorporates a conveyor assembly running the length of the bed. It therefore is of a box-like shape rather than a U-shaped vehicle which can nest or interconnect for pulling and pushing articles. British Patent No. 1,059,656 uses a flexible articulated frame shown in FIG. 5, which lifts and bends during lifting to scoop earth. British Patent No. 1,059,656 also incorporates a conveyor system into is bed for materials handling and movement. The conveyor system bed of British Patent No. 1,059,656 thus prevents its use with interchangeable beds or modules.
Moehr, U.S. Pat. No. 3,306,478 is another example of a low profile, self loading hauling and dumping vehicle. Kress, U.S. Pat. No. 4,026,430 is a mobile carrier for large scrap steel carrying boxes. Wardle, U.S. Pat. No. 2,795,430 is a carry-all with claw loading scraper apron to assist in loading. Muotka et al., U.S. Pat. No. 3,520,432 utilizes a box frame which requires a blade 4 to rearwardly transport materials to the rear of the bed. Quenzi, U.S. Pat. No. 4,505,638 is another example of a box frame, utilizing a horizontal pair of tracks along which its bucket travels. Wilson, U.S. Pat. No. 3,235,983 is another earth moving apparatus. Galis, U.S. Pat. No. 3,826,387 is a self loading and self-propelled haulage vehicle. Niva, U.S. Pat. No. 4,556,356 is a U-frame truck for handling and transportation of containers or receptacles. Robb, U.S. Pat. No. 2,679,119 discloses an auxiliary scraper and loading apron. Bodine, U.S. Pat. No. 3,030,715 discloses a sonic wave earth digging and moving machine. Trieschmann, U.S. Pat. No. 3,273,732 is a self loading vehicle and dump gate therefore. Le Tourneau, U.S. Pat. No. 1,891,266 discloses a scraper. Lichtenberg, U.S. Pat. No. 2,654,165 discloses a carry-type scraper with front digger moving means. Countryman, U.S. Pat. No. 3,937,345 is a shovel loader with ejector bucket. Shackley, Canadian Pat. No. 681,266 is a vehicle provided with a drag line loader.
Cited for general interest is Cohen, U.S. Pat. No. 4,065,825, and Nishibori, Japan No. 62-125952 showing an all wheel independent steering gear.
Applicant's invention described below eliminates the pulling traction problems, while providing an efficient transport and service vehicle with a centrally located operator station. It has independent wheel drive and suspension which can move laterally, if desired, for greater mobility. Applicant's U-shaped frame multi-purpose vehicle can also nest with one another to enable a number of them to be aligned in a lesser space than conventional vehicle for pulling heavy objects. They also may be interconnected front to back in a formation which insures that the wheels of the trailing vehicles do not follow in the same tracks as the forward vehicles.